








key: cord-274230-old0xmcc
authors: Zhao, Qianwen; Meng, Meng; Kumar, Rahul; Wu, Yinlian; Huang, Jiaofeng; Deng, Yunlei; Weng, Zhiyuan; Yang, Li
title: Lymphopenia is associated with severe coronavirus disease 2019 (COVID-19) infections: A systemic review and meta-analysis
date: 2020-05-04
journal: Int J Infect Dis
DOI: 10.1016/j.ijid.2020.04.086
sha: 
doc_id: 274230
cord_uid: old0xmcc

Abstract Objectives Coronavirus Disease 2019 (COVID-19) is a new respiratory and systemic disease which needs quick identification of potential critical patients. This meta-analysis aimed to explore the relationship between lymphocyte count and the severity of COVID-19. Methods Comprehensive systematic literature search was carried out to find studies published from December 2019 to 22 March 2020 from five Databases. The language of literatures included English and Chinese. Mean difference (MD) of lymphocyte count in COVID-19 patients with or without severe disease and odds ratio (OR) of lymphopenia for severe form of COVID-19 was evaluated with this meta-analysis. Results Overall 13 case-series with a total of 2282 cases were included in the study. The pooled analysis showed that lymphocyte count was significantly lower in severe COVID-19 patients (MD -0.31×109/L; 95%CI: -0.42 to -0.19×109/L). The presence of lymphopenia was associated with nearly threefold increased risk of severe COVID-19 (Random effects model, OR=2.99, 95% CI: 1.31-6.82). Conclusions Lymphopenia is a prominent part of severe COVID-19 and a lymphocyte count of less than 1.5×109/L may be useful in predicting the severity clinical outcomes.

Microsoft Excel was used to analyze the clinical symptoms and the laboratory results.

A meta-analysis was carried out using R software (version 3.6.3, available on 125 https://www.r-project.org). Heterogeneity among studies was tested using the Cochran 126 Chi-square test and I 2 , When I 2 < 50%, a fixed-effects model was used, while when 127 I 2 > 50%, a random-effects model was selected. If statistical heterogeneity was found 128 among the results, a further sensitivity analysis was conducted to determine the source 129 of heterogeneity. After the significant clinical heterogeneity was excluded, the 130 randomized effects model was used for meta-analysis. Funnel plot were used to detect 131 publication bias. P <0.05 was considered as statistical significance. Five studies reported the relationship between lymphopenia and the severity of 170 COVID- 19[11, 12, 15, 18, 19] . Lymphopenia was defined as a lymphocyte count of 171 less than 1.1×10 9 /L in four studies [11, 12, 16, 18] , and as less than 1.5×10 9 /L in 172 one [19] . The pooled OR as summarized in Figure 2C shows that the presence of After excluding this study, the I 2 of heterogeneity reduced to 48%, the OR of 178 lymphopenia was 2.17 (95% CI: 1.0126-4.6812). The funnel plot indicated no 179 publication bias inside this study ( Figure 2D ). In addition, another drawback of our study is that there is no data relating to 

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Acknowledgments: Not applicable.

